The irreversibility of relativistic time-dilation

TL;DR

This paper investigates how relativistic effects, including gravity, influence the fundamental fluctuation relations and the emergence of entropy production, revealing an inherent irreversibility in relativistic time-dilation scenarios.

Contribution

It demonstrates that relativistic and gravitational time-dilation effects inherently lead to positive entropy production, extending fluctuation relations into relativistic regimes.

Findings

Relativistic time-dilation contributes to entropy production.

Gravitational effects reinforce irreversibility in fluctuation relations.

Time-reversal symmetry is broken in relativistic contexts.

Abstract

The fluctuation relations, which characterize irreversible processes in Nature, are among the most important results in non-equilibrium physics. In short, these relations say that it is exponentially unlikely for us to observe a time-reversed process and, thus, establish the thermodynamic arrow of time pointing from low to high entropy. On the other hand, fundamental physical theories are invariant under time-reversal symmetry. Although in Newtonian and quantum physics the emergence of irreversible processes, as well as fluctuation relations, is relatively well understood, many problems arise when relativity enters the game. In this work, by considering a specific class of spacetimes, we explore the question of how the time-dilation effect enters into the fluctuation relations. We conclude that a positive entropy production emerges as a consequence of both the special relativistic and the gravitational (enclosed in the equivalence principle) time-dilation effects.